Wireless networks are telecommunications networks that use both wire and radio waves to carry information from one node in the network to a one or more receiving nodes in the network. Cellular telephony is characterized by the use of radio cells that provide radio coverage for a set geographic area, with multiple cells arranged to provide contiguous radio coverage. The first generation of wireless telephone technology were analog mobile phones. As technology progressed a second generation (2G) of wireless service was introduced. The main difference between 1 G systems and 2 G systems were that radio signals in 1 G networks were primarily analog, while 2 G networks were digital. Second generation technologies were primarily based on time division multiplexed access (TDMA) and code division multiplexed access (CDMA). Networks that were upgraded to handle higher-speed data transfer are referred to as 2.5 G and 3 G networks. The 3rd Generation Partnership Project (3GPP) and the 3rd Generation Partnership Project 2 (3GPP2), respectively, developed GSM/UMTS and cdmaOne/CDMA2000 technologies. The next evolution is 4 G technology, which appears to be a version of Universal Mobile Telecommunications System (UMTS).
Wireless communication systems and networks are used in connection with many applications, including, for example, satellite communications systems, portable digital assistants (PDAs), laptop computers, and mobile nodes (e.g., cellular telephones). One significant benefit that users of such applications obtain is the ability to connect to a network (e.g., the Internet) as long as the user is within range of such a wireless communication system. Current wireless communication systems use either, or a combination of, circuit switching and packet switching in order to provide mobile data services to a mobile node. Generally speaking, with circuit-based approaches, wireless data is carried by a dedicated (and uninterrupted) connection between the sender and recipient of data using a physical switching path. Once the direct connection is set-up, it is maintained for as long as the sender and receiver have data to exchange. The establishment of such a direct and dedicated switching path results in a fixed share of network resources being tied up until the connection is closed. When the physical connection between the sender and the receiver is no longer desired, it is tom-down and the network resources are allocated to other users as necessary.
Packet-based approaches, on the other hand, do not permanently assign transmission resources to a given call, and do not require the set-up and tear-down of physical connections between a sender and receiver of data. In general, a data flow in packet-based approaches is “packetized.” That is, the data is divided into separate segments of information, and each segment receives “header” information that may provide, for example, source information, destination information, information regarding the number of bits in the packet, priority information, and security information. The packets are then routed to a destination independently, based on the header information. The data flow may include a number of packets or a single packet.
By a mobile node's very nature on a wireless network, the mobile node can move around the network. In order for the mobile node to continue receiving information properly from the network, an agent can be used to provide mobility management. When a mobile node (e.g., a cell phone, PDA, or BLACKBERRY device) is roaming on a wireless network, it can communicate with a visited network. This agent provides an address to the mobile node to identify the mobile node in the network. This address can be dynamically or statically assigned. Many issues can arise depending on the setup of the wireless network in keeping track of the mobile node and providing mobility management.